The physical perspective on the solid and molten states associated with the mechanical properties of eco‐friendly HDPE/Pinus taeda wood‐plastic composites

The manufacture of wood plastic composites (WPCs) by reutilizing post-consumed polymeric materials and post-industry wood wastes contributes to reduce the environmental impact and the consumption of virgin plastics. In this work, the influence of interfacial adhesion on the solid and molten states of high density polyethylene (HDPE) containing WPCs wood dust of recycled Pinus taeda (PT) was evaluated. The composites were prepared by extrusion in a twin screw extruder using maleic anhydride as compatibilizer. The samples were analyzed by dynamic-mechanical analysis (DMA), tensile and impact strength measurements, oscillatory rheometry, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). DMA analysis showed increase in module and an improved interface with physical interaction between the WPCs phases. The higher molecular interactivity interface improved the mechanical properties relative to pure HDPE. Melting state analysis showed increased WPCs flow restriction, this feature being correlated with reduction in the molecular degree of freedom during flow, which consequently reduces the crystalline degree changes in microstructure as well as in processing parameters of the material. These results lead to consider the development of an eco-friendly and economic effective technology to reuse abundant recycled solid wastes in a new market. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42887.